Arrangement and method for detecting possible positioning problems for devices and device holders attached to a vehicle rail

Abstract

Arrangement for detecting possible positioning problems in devices (12) and device holders (26, 28) attached to a vehicle rail (10), comprising at least one acceleration sensor for detecting accelerations in three spatial directions and an evaluation unit for analyzing the detected acceleration data.

Description

TECHNICAL AREA OF INVENTION

[0001] The invention relates to an arrangement and a method for detecting possible positioning problems for devices attached to a vehicle rail, in particular electronic devices such as wheel sensors and device mounts. BACKGROUND OF THE INVENTION

[0002] For various reasons, there is a need to attach devices, especially electronic devices such as sensors and switching devices, to vehicle tracks, such as railway tracks, for which appropriate device brackets are required.

[0003] Numerous device mounting systems for attaching devices to vehicle rails (hereinafter also referred to as rails) have already been proposed. These can be broadly categorized according to whether mounting the device requires drilling through a rail section, usually the so-called rail web, or whether it is clamped to a rail section, usually the so-called rail foot, without drilling. Device mounting systems of the first type are known, for example, from DE 32 34 651 A1, DE 199 15 598 A1, and DE 10 2013 012 084 B4. Device holders of the second type are known, for example, from DE 695 741 C1, EP 1 960 603 B1 and DE 974 202 C1, wherein, according to all three documents, device holders are clamped to the rail base and wherein the last two documents show height-adjustable device holders.

[0004] The most common and safety-related application of such device mounts is the mounting of so-called wheel sensors, also known as track switches, although the invention is not limited to such electronic devices.

[0005] Wheel sensors are regularly used to monitor track sections to determine whether a rail vehicle, especially a train, is present. This is achieved, for example, by inductively detecting how many wheels (and thus axles; in railway engineering, this is usually referred to as axle counting and axle counting circuits) have passed over sensors located on the rails at the beginning and end of a monitored track section. This allows the system to determine whether another rail vehicle is permitted to enter the track section.

[0006] For such sensors and other devices to function correctly, their precise positioning on a rail is crucial, especially adjusting the distance between the top of the device and the top of the rail's running surface, commonly referred to as height adjustment. The challenge of achieving an exact height adjustment isn't limited to the initial installation of a device on a rail. Wear and subsequent modifications often significantly erode the running surface, considerably reducing the distance between the top of the device and the top of the running surface. This can render certain settings, such as device calibration, inaccurate, potentially leading to faulty measurements, particularly with sensors. In extreme cases, a device can even be damaged by a passing wheel.

[0007] Adjusting the height is far from trivial in the work environment in question. Equipment mounts must be able to withstand loads of several hundred, sometimes even over a thousand grams, which can occur when a very fast train passes over a section of track to which a equipment mount is attached. In addition to these mechanical loads, thermal stresses are also regularly present.

[0008] To at least partially solve the problem of height adjustment, height-adjustable device mounts are known from the aforementioned publications EP 1 960 603 B1 and DE 974 202 C1. Each mount comprises a base bracket with two clamping jaws, which is fixed to a vehicle rail, and an adapter plate, which can be fixed to the base bracket in various relative positions to the base bracket, for mounting a device to be attached to the vehicle rail. The solution known from EP 1 960 603 B1 allows the typically very heavy base bracket to be fixed to the rail first, and then the adapter plate to be fixed to the base bracket at a specific mounting height. In contrast, the solution known from DE 974 202 C1 uses a single clamping screw to clamp both the adapter plate against one of the two clamping jaws of the base bracket and the two clamping jaws against the rail foot.It should be noted at this point that the technical term "adapter plate" does not necessarily refer to an actual plate-shaped (flat) component. Rather, the adapter plate can have various suitable designs and, for example, be shaped like a T-beam or a box. By using different adapter plates, different devices can be attached to one and the same base. In this text, the term "adapter plate" therefore refers not to the precise three-dimensional shape of the component so named, but to its function. BRIEF SUMMARY OF THE INVENTION

[0009] While existing solutions allow for fairly precise positioning of a device on a vehicle rail, the aforementioned stresses cause the devices to loosen over time and no longer be positioned correctly for proper functioning. This problem is particularly pronounced when the device mounts—advantageous in themselves for precise positioning—have various parts that can be positioned relative to each other, such as a base mount that attaches directly to a rail and an adapter plate that connects the device to the base mount. In such cases, both the connection between the adapter plate and the base mount, and the connection between the adapter plate and the device, can loosen or even detach completely, potentially leading to a shift in the device's position.

[0010] If the device is an inductively operating wheel sensor, it is known to at least partially solve the problem of detecting position changes by providing additional inductively operating resonant circuits on the sensor and aligning them so that they are damped in their correct operating position by a part of the rail to which the wheel sensor is attached, for example, by the rail foot, or by a separate component. However, not all devices are suitable for the installation of such additional resonant circuits, which are also complex to manufacture, require a relatively large amount of space, and increase the weight of the device, and thus amplify the vibrations transmitted from the device to the (if present) adapter plate, or at least to the base mount.Furthermore, the resonant circuits are limited in their detection capabilities - typically they only respond when the position of the device has changed significantly or it has even completely fallen off the rail.

[0011] Based on this, the invention aims to provide an arrangement and a method for detecting possible positioning problems for devices attached to a vehicle rail, in particular electronic devices such as wheel sensors, and device holders, which makes it possible to detect positioning problems, for example due to loosening, deformation or damage to the attachment of a device and / or a device holder to a vehicle rail, in a simple and particularly reliable manner.

[0012] The problem is solved by an arrangement with the features of claim 1 or a method with the features of claim 8. Dependent claims 13 and 15 relate to a device or a device holder with an arrangement according to the invention. Dependent claim 17 relates to the use of at least one acceleration sensor for detecting potential positioning problems in a device mounted on a vehicle rail or in a device holder mounting a device on a vehicle rail. The dependent claims relate to advantageous embodiments and further developments.

[0013] An arrangement according to the invention for detecting potential positioning problems in devices and device mounts attached to a vehicle rail comprises at least one accelerometer for detecting accelerations in three spatial directions and an evaluation unit for analyzing the detected acceleration data, thereby achieving several advantages. For example, accelerometers usable according to the invention are now inexpensive and lightweight components with a small footprint, which can be connected via standard interfaces in a simple and cost-effective manner to a corresponding evaluation unit for data analysis. This evaluation unit can be a separate unit or a unit provided by a device to be mounted on a rail. Unlike known resonant circuits, they can detect not only changes in a relative position but also the actual orientation in space.Their energy requirements are extremely low, and standard sensors are available that can reliably withstand even the extremely high acceleration forces in question here.

[0014] At least one accelerometer can be arranged on or in a device holder or on or in a device attached to a vehicle rail. The detection of potential positioning problems can be improved by positioning multiple accelerometers at different locations. This also advantageously allows for redundancy, which is frequently required in the railway sector.

[0015] In a preferred embodiment, the evaluation unit is designed to detect changes in the position of the at least one accelerometer. Depending on the specific application, this can involve detecting an absolute position (orientation) in space or a relative position. Alternatively, or preferably additionally, the evaluation unit can be designed to detect changes in the vibration behavior of the at least one accelerometer when a rail vehicle passes by. This makes it possible, particularly in combination with position detection and vibration behavior detection, to identify potential positioning problems early and reliably. For example, it can happen that the device or its mounting becomes loose, but the device is still in a correct or at least tolerable position during a position measurement (perhaps purely by chance).Loose connections between the device and / or its mounting and / or the rail typically lead to significantly stronger vibrations, especially when a train passes. This makes it possible to detect positioning problems before they actually impair the device's function. If such changes are detected, a warning signal can be automatically generated if the detected changes are outside predefined limits. Depending on the application, the warning signal can be a visual and / or audible signal emitted by the device or its mounting. Typically, however, the warning signal is automatically transmitted to a higher-level control unit, such as a signal box or other control center, from which further measures can then be initiated automatically or manually.It is also possible to provide different graded warning signals, for example signals indicating that the detected changes are still within a permissible tolerance range, but that the changes indicate that more serious positioning problems may occur soon.

[0016] An inventive method for detecting potential positioning problems in devices mounted on a rail comprises continuously or discontinuously acquiring acceleration data in three spatial directions on or in a device mounted on a rail or on or in a device holder that mounts the device to the rail, and evaluating the acquired acceleration data, at least with regard to the current position of the device and / or the device holder and / or the vibration behavior of the device and / or the device holder when a rail vehicle passes by. Depending on the application and, for example, applicable standards, the person skilled in the art can advantageously choose whether the acquisition of the acceleration data is continuous, for example at predetermined time intervals, or discontinuous, for example within a specific time window before, during, and after a train passes by.The recording can also be triggered remotely by a higher-level control unit, for example as part of certain audits.

[0017] In a preferred implementation, the evaluation of the recorded acceleration data includes a comparison with previously recorded acceleration data and / or with predefined target values. Here, too, the person skilled in the art can advantageously choose the implementation method that is particularly suitable for the respective application. Hybrid methods are also possible. For example, it can be predefined that vibrations must remain below certain target values, while no exact specifications are given for the position. Instead, the position determined after the initial mounting of the device or device bracket on a rail and testing of the device for operational readiness is used as a reference value. The position is thus derived from the values ​​of the acceleration due to gravity measured in three different directions, typically perpendicular to each other.If the accelerometer were aligned so that one of its axes points exactly vertically downwards, the corresponding acceleration value would be approximately 9.81 m / s², depending on the location. 2 , while the acceleration in the other two directions would be 0. As a person skilled in the art can see, the sensor does not need to be specially aligned to detect changes in position or vibration behavior.

[0018] In an advantageous embodiment, the evaluation of the acceleration data includes determining a long-term trend with respect to the position and / or vibration behavior. This advantageously allows potential positioning problems to be identified before they actually occur. For example, vibrations may increase or the position of, say, a wheel sensor may change without the vibrations or the position falling outside the respective permissible tolerance ranges. However, a clear trend can indicate that problems will arise in the future, so that appropriate measures can be taken, for example, during routine maintenance work.

[0019] Further details and advantages of the invention will become apparent from the following purely exemplary and non-limiting description of embodiments in conjunction with the drawing comprising six figures. BRIEF DESCRIPTION OF THE DRAWING Fig. Figure 1 shows a highly schematic representation of a section of a rail along with a device holder attached to it, containing an electronic device. DESCRIPTION OF PREFERRED EXECUTION FORMS

[0020] The Fig. Figure 1 schematically shows a section of a rail, designated as a whole by 10, together with a device holder arranged thereon, and an electronic device, designated as a whole by 12. The device is a typical wheel sensor with a sensor plate 14 and a sensor housing 16. The invention can be advantageously used with such wheel sensors, but is also fundamentally suitable for any other devices mounted on rails.

[0021] The section of rail 10 shown is a typical railway rail with a rail head 18, the upper side of which forms a running surface 20, a rail web 22 and a rail foot 24.

[0022] In the illustrated embodiment of a device holder, a base holder 26 engages the rail foot 24. It comprises two clamping jaws that clamp the rail foot 24 between them by means of one or more clamping screws. The device holder shown is therefore one of those that does not require drilling through the rail 10. However, the arrangement according to the invention for detecting potential positioning problems is not limited to this type of device holder. The base holder can, for example, also be attached to the rail web 22 via corresponding bores and retaining screws.

[0023] The device holder further comprises an adapter plate 28, wherein the adapter plate 28 and the base holder 26 are fixed in this embodiment by means of two clamping screws which are guided in two elongated holes 30 in a height-adjustable manner. To clarify the design of an adapter plate 28, the schematic representation of the Fig.1. Both the clamping screws, which actually penetrate the two elongated holes 30 in the adapter plate 28 to fix the adapter plate 28 relative to the base 26, and the fastening screws, which actually penetrate the two mounting openings 32 to attach the device 12 to the adapter plate 28, have been omitted. The technical term "height-adjustable guide" refers to the fact that by sliding the adapter plate along the elongated holes 30, the distance of the device 12 to the running surface of the rail 10, and thus the height of the device 12 above the rail foot 24, can be changed. The arrangement according to the invention is suitable not only for height-adjustable device holders and multi-part device holders, which, like the one shown, consist of a base holder and an adapter plate, but for all types of device holders.

[0024] With the device mount shown, the clamping jaws, the connection between adapter plate 28 and base mount 26, or the connection between adapter plate 28 and device 12 may loosen or detach completely due to accidental or intentional damage. Loosening can manifest itself, for example, as a change in the device's position relative to the rail or, if this position happens to be correct, as increased vibrations, especially when a rail vehicle passes by. Even if a connection is completely detached and the device lies loose next to the rails, its position in space typically changes, recognizable by different gravitational accelerations in the three spatial directions, as does its vibration behavior.

[0025] To enable the early detection of such positioning problems, the invention provides an arrangement, not visible in the figure since it is housed within the device 12, more precisely within the sensor housing 16, consisting of at least one accelerometer for detecting accelerations in three spatial directions and an evaluation unit for analyzing the detected acceleration data. This allows for the examination of various data and the acquisition of insights that advantageously enable the early detection of problems such as the described loosening of connections, before malfunctions occur. For example, the evaluation unit can be designed to detect changes in the position of the at least one accelerometer and / or changes in the vibration behavior of the at least one accelerometer when a rail vehicle passes by.If such changes are detected, the evaluation unit can be designed to generate a warning signal if the detected changes are outside predetermined limits, and this warning signal can then be sent to a higher-level control unit. Advantageously, multiple accelerometers can also be used, the data from which can be compared to test the correct functioning of the accelerometers.

[0026] Accelerometers of the type used here measure accelerations—in the state of rest simply the acceleration due to gravity—in three spatial directions, usually three mutually perpendicular directions, most often designated x, y, and z. To detect positioning problems according to the invention, no special orientation of the accelerometers is necessary. In the illustrated example of a wheel sensor 12, for instance, it can be attached to a rail 10 and aligned so that it optimally fulfills its intended function. Once the wheel sensor 12 is correctly aligned, it is fixed in this position by tightening the corresponding clamping and / or locking screws. At least one accelerometer is fixedly arranged in the housing 16, for example by potting, such that it follows all movements of the housing 16.The acceleration data measured in the three spatial directions after the wheel sensor 12 is fixed are read out and can form target values ​​against which deviations are then determined. For example, if accelerations of 0.4 g each are measured in the x and y directions, it can be provided that if, for example, 0.3 g is measured in the x direction and 0.5 g in the y direction during a subsequent measurement, a change in position outside a previously defined tolerance range is detected, whereupon, for example, a corresponding warning signal can be generated and sent to a higher-level control unit, from where appropriate measures can then be triggered.If only a specific trend is detected, but the position of the wheel sensor 12 remains within the tolerance range, this can also be reported to the higher-level control unit. Such a report may then have a lower urgency than if the position of the wheel sensor 12 has moved into a critical range. If the position of the wheel sensor 12 is not critical, the control unit can, for example, initiate a more detailed inspection of the wheel sensor as part of a routine check. If, on the other hand, the position of the wheel sensor 12 is critical, immediate on-site maintenance can be initiated.

[0027] Similarly, target values ​​for specific vibration behavior can be defined by first measuring the vibration behavior during several typical train passages. It can even be planned to create different vibration profiles for different train types (freight trains, high-speed trains) and store them in a way that is accessible to the evaluation unit. Using appropriate communication methods, the evaluation unit can then be informed during operation which type of train is passing, so that it can compare the currently measured vibrations with the correct vibration profile and generate corresponding warning signals in case of certain deviations.

[0028] Within the scope of the inventive concept defined by the claims, numerous modifications and further developments are possible, relating, for example, to communication between the evaluation unit and the higher-level control unit. For instance, it can be provided that data from the at least one accelerometer are sent to the higher-level control unit at regular intervals, where they are preferably evaluated using AI, for example, to confirm certain setpoints or to detect trends. Generally, the evaluation unit does not have to be located close to the at least one accelerometer, but can be situated at a distance from it. REFERENCE MARK LIST 10 rail 12 Device (here: wheel sensor) 14 Sensor plate 16 sensor housings 18 Railhead 20 tread surface 22 rail bridge 24 rail foot 26 Base bracket 28 Adapter plate 30 slotted holes 32 Mounting opening QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 32 34 651 A1

[0003] DE 199 15 598 A1

[0003] DE 10 2013 012 084 B4

[0003] DE 695 741 C1

[0003] EP 1 960 603 B1 [0003, 0008] DE 974 202 C1 [0003, 0008]

Claims

[1] Arrangement for detecting possible positioning problems in equipment and equipment holders attached to a vehicle rail, comprising: - at least one accelerometer for detecting accelerations in three spatial directions and - an evaluation unit for analyzing the recorded acceleration data. [2] Arrangement according to claim 1, characterized by that at least one accelerometer is located on or in a device holder. [3] Arrangement according to claim 1 or 2, characterized by that at least one acceleration sensor is arranged on or in a device attached to a vehicle rail. [4] Arrangement according to any one of the preceding claims, characterized by that the evaluation unit is designed to detect changes in the position of at least one acceleration sensor. [5] Arrangement according to any one of the preceding claims, characterized bythat the evaluation unit is designed to detect changes in the vibration behavior of at least one acceleration sensor when a rail vehicle passes by. [6] Arrangement according to claim 4 or 5, characterized by that the evaluation unit is designed to generate a warning signal when the detected changes are outside predetermined limits. [7] Arrangement according to claim 6, characterized by that the arrangement is designed to send the warning signal to a higher-level control unit. [8] Methods for detecting possible positioning problems in devices and device holders attached to a vehicle rail, comprising: - continuous or discontinuous acquisition of acceleration data in three spatial directions on or in a device attached to a vehicle rail or on or in a device holder attaching the device to the vehicle rail, - Evaluating the recorded acceleration data, at least with regard to the current position of the device and / or the device mount and / or the vibration behavior of the device and / or the device mount when a rail vehicle passes by. [9] Method according to claim 8, characterized by , that the evaluation of the recorded acceleration data includes a comparison with previously recorded acceleration data and / or with predefined target values. [10] Method according to claim 9, characterized by , that if deviations of the recorded acceleration data from the previously recorded acceleration data and / or from the predefined target values ​​exceed predetermined limits, a warning signal is automatically generated. [11] Method according to claim 10, characterized by that the warning signal is automatically transmitted to a higher-level control unit. [12] Method according to any one of claims 8 to 11, characterized by, that the evaluation of the acceleration data includes determining a long-term trend regarding the position and / or vibration behavior. [13] Device, in particular an electronic device such as a wheel sensor, for mounting on a vehicle rail, comprising an arrangement of - at least one accelerometer for detecting accelerations in three spatial directions and - an evaluation unit for analyzing the recorded acceleration data. [14] Device according to claim 13, wherein the arrangement is configured according to any one of claims 4 to 7. [15] Device holder, in particular height-adjustable device holder for attaching devices to a vehicle rail, comprising an arrangement of - at least one accelerometer for detecting accelerations in three spatial directions and - an evaluation unit for analyzing the recorded acceleration data. [16] Device holder according to claim 15, wherein the arrangement is designed according to any one of claims 4 to 7. [17] Use of at least one acceleration sensor to detect possible positioning problems in a device attached to a vehicle rail or a device holder attaching a device to a vehicle rail.

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